Can You Dispute the Results of a BAC Test in Illinois?

 Posted on July 13, 2021 in DUI

Naperville IL DUI defense attorneyDriving under the influence may result in significant penalties in Illinois, including driver’s license suspension, mandatory alcohol education classes, and in some cases, even jail time. DUI penalties are especially severe if there are certain aggravating circumstances present or it is not the defendant’s first DUI. If you or a loved one was arrested and charged with drunk driving based on the results of a chemical blood alcohol content (BAC) test, you may wonder if these test results may be disputed.

Contesting the Result of a Breath Alcohol Test

In Illinois, a driver is intoxicated “per se,” or automatically considered to be intoxicated, if his or her blood alcohol content is 0.08 percent or greater. Most police officers carry a portable breath test often referred to as a breathalyzer. These preliminary tests are typically used to establish probable cause for the DUI arrest. However, the results of a preliminary roadside BAC test alone are not enough to secure a conviction. Usually, after someone is arrested for DUI, they are issued a secondary test at the police station. These evidentiary tests are considered to be more reliable than the roadside test. However, several issues can cause a BAC test to be inaccurate, including:

  • Inadequate cleaning and maintenance of the testing device

  • Defects with the testing device

  • Infrequent calibration

  • The defendant’s medical conditions

  • The timing of the test

  • How the test is administered

A skilled DUI defense lawyer can help you determine if such issues may have led to unreliable BAC test results. If the breath test results were inaccurate, you may be able to avoid a conviction.

Blood Tests Are Not Always Admissible

Police may also ask someone arrested for driving under the influence to submit to a blood test. While blood tests are usually considered to be more precise than breath tests, there are several reasons that blood test results may be excluded from a DUI case. For example, blood tests may be inadmissible if the blood sample was not stored properly. For instance, if the sample was not sealed properly, it may be contaminated. Blood that is stored improperly may ferment, which raises the alcohol concentration in the sample.

Another possible defense is to allege that the driver’s BAC was not over the legal limit when they were driving. Because of the way alcohol is metabolized, someone’s BAC may continue to rise after they have stopped drinking. Therefore, it is possible that a driver’s BAC was below the legal limit while they were driving but above the limit when they submitted to the test.

Contact a Naperville DUI Defense Lawyer

If you or a loved one was arrested and charged with DUI, contact a DuPage County DUI defense attorney from J. Aldrich Law, P.C. for help. Call us at 630-953-3000 for a free, confidential consultation.



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